Signal scrambling sequence techniques for wireless communications

ABSTRACT

Techniques for scrambling sequence generation may provide scrambling for a reference signal, a control signal, or a data signal that is independent of a center frequency of a wireless system bandwidth. Generated scrambling sequences may allow for demodulation of signals in which a synchronization channel does not share a same center frequency as the wireless system bandwidth.

CROSS REFERENCES

The present Application for Patent is a continuation of U.S. patentapplication Ser. No. 15/865,738 by SUN, et al., entitled “SIGNALSCRAMBLING SEQUENCE TECHNIQUES FOR WIRELESS COMMUNICATIONS” filed Jan.9, 2018, which claims priority to U.S. Provisional Patent ApplicationNo. 62/445,127 by SUN, et al., entitled “SIGNAL SCRAMBLING SEQUENCETECHNIQUES FOR WIRELESS COMMUNICATIONS,” filed Jan. 11, 2017, assignedto the assignee hereof.

BACKGROUND

The following relates generally to wireless communication, and morespecifically to signal scrambling sequence techniques for wirelesscommunications.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, and orthogonal frequencydivision multiple access (OFDMA) systems, (e.g., a Long Term Evolution(LTE) system, or a New Radio (NR) system). A wireless multiple-accesscommunications system may include a number of base stations or accessnetwork nodes, each simultaneously supporting communication for multiplecommunication devices, that may be otherwise known as user equipment(UE).

In a LTE or LTE-Advanced (LTE-A) network, a set of one or more basestations may define an eNodeB (eNB). In other examples (e.g., in a nextgeneration new radio (NR) or 5G network), a wireless multiple accesscommunication system may include a number of smart radio heads (RHs) incommunication with a number of access node controllers (ANCs), where aset of one or more RHs, in communication with an ANC, defines a basestation (e.g., an eNB or gNB). A base station may communicate with a setof UEs on downlink (DL) channels (e.g., for transmissions from a basestation to a UE) and uplink (UL) channels (e.g., for transmissions froma UE to a base station).

A base station in some LTE or NR deployments may transmit downlinktransmissions to one or more UEs, and the one or more UEs may transmituplink transmissions back to the base station. In some cases,transmissions may be demodulated based on a scrambling sequence. Forexample, a control channel transmission may be demodulated based on areference signal that is received from a same transmitter that transmitsthe control channel transmission. The reference signal may be scrambled,and the scrambling value for each frequency tone in the reference signalmay be a function of a predetermined algorithm (e.g., based on anidentification of the transmitter, an index value of the transmission, achannel center frequency, etc.). A receiver that receives the signal maydescramble the signal, according to a determined scrambling sequence,and decode the signal. In cases where the signal is a reference signal,the reference signal may be used for demodulating other transmissions.

SUMMARY

The described techniques relate to improved methods, systems, devices,or apparatuses that support signal scrambling sequence techniques forwireless communications. Generally, the described techniques provide foridentification of a scrambling sequence used for a reference signal, acontrol signal, or a data signal that is independent of a centerfrequency of a wireless system bandwidth. Such identification ofscrambling sequences may allow for demodulation of signals in which asynchronization channel does not share a same center frequency as thewireless system bandwidth. In some examples, a synchronization channelmay be identified that provides location information for a commoncontrol resource set. A scrambling sequence for one or more of areference signal, a control signal, or a data signal, may be determinedfor use in demodulating the common control resource set, and one or moreof the reference signal, the control signal, or the data signal, may beprocessed based at least in part on the scrambling sequence. In somecases, a cell ID and a slot or subframe index for the common controlresource set may be determined, and the scrambling sequence identifiedfor one or more of the reference signal, the control signal, or the datasignal, based on the cell ID and slot or subframe index. In some cases,a number of different numerologies may be available in a wirelesscommunications system, and the slot or subframe index may be based on areference numerology of the number of available numerologies.

A method of wireless communication is described. The method may includeidentifying a synchronization channel containing location informationfor a common control resource set within a system bandwidth, determininga location of the common control resource set within the systembandwidth based at least in part on the location information,determining a scrambling sequence for one or more of a reference signal,a control signal, or a data signal, for use in demodulating the commoncontrol resource set, and processing one or more of the referencesignal, the control signal, or the data signal, based at least in parton the scrambling sequence.

An apparatus for wireless communication is described. The apparatus mayinclude means for identifying a synchronization channel containinglocation information for a common control resource set within a systembandwidth, means for determining a location of the common controlresource set within the system bandwidth based at least in part on thelocation information, means for determining a scrambling sequence forone or more of a reference signal, a control signal, or a data signal,for use in demodulating the common control resource set, and means forprocessing one or more of the reference signal, the control signal, orthe data signal, based at least in part on the scrambling sequence.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to identify a synchronization channelcontaining location information for a common control resource set withina system bandwidth, determine a location of the common control resourceset within the system bandwidth based at least in part on the locationinformation, determine a scrambling sequence for one or more of areference signal, a control signal, or a data signal, for use indemodulating the common control resource set, and process one or more ofthe reference signal, the control signal, or the data signal, based atleast in part on the scrambling sequence.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to identify a synchronizationchannel containing location information for a common control resourceset within a system bandwidth, determine a location of the commoncontrol resource set within the system bandwidth based at least in parton the location information, determine a scrambling sequence for one ormore of a reference signal, a control signal, or a data signal, for usein demodulating the common control resource set, and process one or moreof the reference signal, the control signal, or the data signal, basedat least in part on the scrambling sequence.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a center frequency ofthe synchronization channel, and wherein the scrambling sequence for oneor more of the reference signal, the control signal, or the data signal,may be determined based at least in part on the center frequency of thesynchronization channel. In some examples of the method, apparatus, andnon-transitory computer-readable medium described above, the centerfrequency of the synchronization channel may be different than a centerfrequency of the system bandwidth.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the scrambling sequence forone or more of the reference signal, the control signal, or the datasignal, may be determined independently of a center frequency of thesynchronization channel or a center frequency of the system bandwidth.Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining a cell ID and a slot orsubframe index for the common control resource set, and determining thescrambling sequence for one or more of the reference signal, the controlsignal, or the data signal, based on the cell ID and slot or subframeindex. In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the slot or subframe index maybe based on a reference numerology of a plurality of availablenumerologies for wireless transmissions within the system bandwidth. Insome examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the reference numerologycorresponds to a 15 kHz tone spacing or multiples thereof.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a raster ofsynchronization channel center frequencies within the system bandwidth.Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a center frequency ofthe synchronization channel as one of the synchronization channel centerfrequencies on the raster of synchronization channel center frequencies.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the processing one or more ofthe reference signal, the control signal, or the data signal, comprisesidentifying a cell ID and a slot or subframe index associated with thecommon control resource set, identifying a center frequency of thesynchronization channel, generating the scrambling sequence based atleast in part on the cell ID, the slot or subframe index, and the centerfrequency of the synchronization channel, and applying the scramblingsequence to a signal pattern of one or more of the reference signal, thecontrol signal, or the data signal.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the processing one or more ofthe reference signal, the control signal, or the data signal, furthercomprises identifying a reference resource element (RE) associated witha received signal, and filling the scrambling sequence for REs of one ormore of the reference signal, the control signal, or the data signal,REs starting at the reference RE based on the generated scramblingsequence. In some examples, identifying the reference RE may compriseidentifying a constant fixed offset based at least in part on at leastone of a physical broadcast channel (PBCH) or remaining minimum systeminformation (RMSI).

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying that the common controlresource set may be transmitted on a second carrier that may bedifferent than a first carrier used to transmit the synchronizationchannel. Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a center frequency of asecond synchronization channel transmitted on the second carrier. Someexamples of the method, apparatus, and non-transitory computer-readablemedium described above may further include processes, features, means,or instructions for determining the scrambling sequence for one or moreof the reference signal, the control signal, or the data signal, for usein demodulating the common control resource set based on the centerfrequency of the second synchronization channel.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a cell ID and a slot orsubframe index for the common control resource set, generating thescrambling sequence based at least in part on the cell ID, the slot orsubframe index, and the reference RE location, and applying thescrambling sequence to reference signal REs starting at the reference RElocation based on the generated scrambling sequence. In some examples,identifying the reference RE location may comprise identifying aconstant fixed offset based at least in part on at least one of a PBCHor RMSI.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a raster ofsynchronization channel center frequencies within the system bandwidth,and identifying a first synchronization channel center frequency as thereference RE location within the system bandwidth. In some examples ofthe method, apparatus, and non-transitory computer-readable mediumdescribed above, the first synchronization channel center frequency maybe selected based on an index of the raster of synchronization channelcenter frequencies and a parameter that identifies a scrambling sequenceor a length of the scrambling sequence.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communicationthat supports signal scrambling sequence techniques for wirelesscommunications in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system thatsupports signal scrambling sequence techniques for wirelesscommunications in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of wireless resources for asynchronization channel relative to a system bandwidth, in accordancewith aspects of the present disclosure.

FIG. 4 illustrates an example of wireless resources for asynchronization channel and for common control information, that supportsignal scrambling sequence techniques for wireless communications inaccordance with aspects of the present disclosure.

FIG. 5 illustrates an example of wireless resources for asynchronization channel and for common control information, that supportsignal scrambling sequence techniques for wireless communications inaccordance with aspects of the present disclosure.

FIG. 6 illustrates an example of a scrambling sequence cycles forwireless communications in accordance with aspects of the presentdisclosure.

FIG. 7 illustrates an example of a process flow that supports signalscrambling sequence techniques for wireless communications in accordancewith aspects of the present disclosure.

FIGS. 8 through 10 show block diagrams of a device that supports signalscrambling sequence techniques for wireless communications in accordancewith aspects of the present disclosure.

FIG. 11 illustrates a block diagram of a system including a UE thatsupports signal scrambling sequence techniques for wirelesscommunications in accordance with aspects of the present disclosure.

FIG. 12 illustrates a block diagram of a system including a base stationthat supports signal scrambling sequence techniques for wirelesscommunications in accordance with aspects of the present disclosure.

FIGS. 13 through 17 illustrate methods for signal scrambling sequencetechniques for wireless communications in accordance with aspects of thepresent disclosure.

DETAILED DESCRIPTION

Improved methods, systems, devices, or apparatuses of various examplesmay be used to support sequence scrambling for reference, control, ordata signals in a wireless communications system. Various describedtechniques provide for identification of a scrambling sequence used fora reference signal, a control signal, or a data signal that isindependent of a center frequency of a wireless system bandwidth. Suchidentification of scrambling sequences may allow for demodulation ofsignals in which a synchronization channel does not share a same centerfrequency as the wireless system bandwidth. In some examples, asynchronization channel may be identified that provides locationinformation for a common control resource set. A scrambling sequence forone or more of a reference signal, a control signal, or a data signal,may be determined for use in demodulating the common control resourceset, and one or more of the reference signal, the control signal, or thedata signal, may be processed based at least in part on the scramblingsequence. In some cases, a cell ID and a slot or subframe index for thecommon control resource set may be determined, and the scramblingsequence identified for one or more of the reference signal, the controlsignal, or the data signal, based on the cell ID and slot or subframeindex. In some cases, a number of different numerologies may beavailable in a wireless communications system, and the slot or subframeindex may be based on a reference numerology of the number of availablenumerologies.

Such techniques may provide for relatively efficient and flexible usageof wireless resources, and may help to enhance the efficiency of awireless network. The present disclosure describes various techniqueswith reference to next generation networks (e.g., 5G or NR networks)that are being designed to support features such as high bandwidthoperations, more dynamic subframe/slot types, and self-containedsubframe/slot types (in which HARQ feedback for a subframe/slot may betransmitted before the end of the subframe/slot). However, suchtechniques may be used for any system in which uplink or downlinktransmissions may be transmitted using scrambling sequences.

Aspects of the disclosure are initially described in the context of awireless communications system. Aspects of the disclosure are furtherillustrated by and described with reference to apparatus diagrams,system diagrams, and flowcharts that relate to signal scramblingsequence techniques for wireless communications.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. In some examples, the wireless communications system100 may be a LTE (or LTE-Advanced) network, or a New Radio (NR) network.In some cases, wireless communications system 100 may support enhancedbroadband communications, ultra-reliable (i.e., mission critical)communications, low latency communications, and communications withlow-cost and low-complexity devices. In some cases, base stations 105and UEs 115 may communicate using scrambling sequences that may bedetermined independently of a system bandwidth and/or a system bandwidthcenter frequency.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Each base station 105 may providecommunication coverage for a respective geographic coverage area 110.Communication links 125 shown in wireless communications system 100 mayinclude uplink (UL) transmissions from a UE 115 to a base station 105,or downlink (DL) transmissions, from a base station 105 to a UE 115.Control information and data may be multiplexed on an uplink channel ordownlink according to various techniques. Control information and datamay be multiplexed on a downlink channel, for example, using timedivision multiplexing (TDM) techniques, frequency division multiplexing(FDM) techniques, or hybrid TDM-FDM techniques. In some examples, thecontrol information transmitted during a TTI of a downlink channel maybe distributed between different control regions in a cascaded manner(e.g., between a common control region and one or more UE-specificcontrol regions).

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile station, a subscriber station, a mobile unit, asubscriber unit, a wireless unit, a remote unit, a mobile device, awireless device, a wireless communications device, a remote device, amobile subscriber station, an access terminal, a mobile terminal, awireless terminal, a remote terminal, a handset, a user agent, a mobileclient, a client, or some other suitable terminology. A UE 115 may alsobe a cellular phone, a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a tabletcomputer, a laptop computer, a cordless phone, a personal electronicdevice, a handheld device, a personal computer, a wireless local loop(WLL) station, an Internet of things (IoT) device, an Internet ofEverything (IoE) device, a machine type communication (MTC) device, anappliance, an automobile, or the like.

In some cases, a UE 115 may also be able to communicate directly withother UEs (e.g., using a peer-to-peer (P2P) or device-to-device (D2D)protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a cell.Other UEs 115 in such a group may be outside the geographic coveragearea 110 of a cell, or otherwise unable to receive transmissions from abase station 105. In some cases, groups of UEs 115 communicating via D2Dcommunications may utilize a one-to-many (1:M) system in which each UE115 transmits to every other UE 115 in the group. In some cases, a basestation 105 facilitates the scheduling of resources for D2Dcommunications. In other cases, D2D communications are carried outindependent of a base station 105.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines, i.e., Machine-to-Machine (M2M) communication. M2M or MTC mayrefer to data communication technologies that allow devices tocommunicate with one another or a base station without humanintervention. For example, M2M or MTC may refer to communications fromdevices that integrate sensors or meters to measure or captureinformation and relay that information to a central server orapplication program that can make use of the information or present theinformation to humans interacting with the program or application. SomeUEs 115 may be designed to collect information or enable automatedbehavior of machines. Examples of applications for MTC devices includesmart metering, inventory monitoring, water level monitoring, equipmentmonitoring, healthcare monitoring, wildlife monitoring, weather andgeological event monitoring, fleet management and tracking, remotesecurity sensing, physical access control, and transaction-basedbusiness charging.

In some cases, an MTC device may operate using half-duplex (one-way)communications at a reduced peak rate. MTC devices may also beconfigured to enter a power saving “deep sleep” mode when not engagingin active communications. In some cases, MTC or IoT devices may bedesigned to support mission critical functions and wirelesscommunications system may be configured to provide ultra-reliablecommunications for these functions.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., S1, etc.). Base stations105 may communicate with one another over backhaul links 134 (e.g., X2,etc.) either directly or indirectly (e.g., through core network 130).Base stations 105 may perform radio configuration and scheduling forcommunication with UEs 115, or may operate under the control of a basestation controller (not shown). In some examples, base stations 105 maybe macro cells, small cells, hot spots, or the like. Base stations 105may also be referred to as eNodeBs (eNBs) 105.

A base station 105 may be connected by an S1 interface to the corenetwork 130. The core network may be an evolved packet core (EPC), whichmay include at least one MME, at least one S-GW, and at least one P-GW.The MME may be the control node that processes the signaling between theUE 115 and the EPC. All user IP packets may be transferred through theS-GW, which itself may be connected to the P-GW. The P-GW may provide IPaddress allocation as well as other functions. The P-GW may be connectedto the network operators IP services. The operators IP services mayinclude the Internet, the Intranet, an IP Multimedia Subsystem (IMS),and a Packet-Switched (PS) Streaming Service (PSS).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. At least some of the networkdevices, such as a base station 105 may include subcomponents such as anaccess network entity, which may be an example of an access nodecontroller (ANC). Each access network entity may communicate with anumber of UEs 115 through a number of other access network transmissionentities, each of which may be an example of a smart radio head, or atransmission/reception point (TRP). In some configurations, variousfunctions of each access network entity or base station 105 may bedistributed across various network devices (e.g., radio heads and accessnetwork controllers) or consolidated into a single network device (e.g.,a base station 105).

Wireless communications system 100 may operate in an ultra-highfrequency (UHF) frequency region using frequency bands from 700 MHz to2600 MHz (2.6 GHz), although in some cases WLAN networks may usefrequencies as high as 4 GHz. This region may also be known as thedecimeter band, since the wavelengths range from approximately onedecimeter to one meter in length. UHF waves may propagate mainly by lineof sight, and may be blocked by buildings and environmental features.However, the waves may penetrate walls sufficiently to provide serviceto UEs 115 located indoors. Transmission of UHF waves is characterizedby smaller antennas and shorter range (e.g., less than 100 km) comparedto transmission using the smaller frequencies (and longer waves) of thehigh frequency (HF) or very high frequency (VHF) portion of thespectrum. In some cases, wireless communications system 100 may alsoutilize extremely high frequency (EHF) portions of the spectrum (e.g.,from 30 GHz to 300 GHz). This region may also be known as the millimeterband, since the wavelengths range from approximately one millimeter toone centimeter in length. Thus, EHF antennas may be even smaller andmore closely spaced than UHF antennas. In some cases, this mayfacilitate use of antenna arrays within a UE 115 (e.g., for directionalbeamforming).

Thus, wireless communications system 100 may support millimeter wave(mmW) communications between UEs 115 and base stations 105. Devicesoperating in mmW or EHF bands may have multiple antennas to allowbeamforming. That is, a base station 105 may use multiple antennas orantenna arrays to conduct beamforming operations for directionalcommunications with a UE 115. Beamforming (which may also be referred toas spatial filtering or directional transmission) is a signal processingtechnique that may be used at a transmitter (e.g. a base station 105) toshape and/or steer an overall antenna beam in the direction of a targetreceiver (e.g. a UE 115). This may be achieved by combining elements inan antenna array in such a way that transmitted signals at particularangles experience constructive interference while others experiencedestructive interference.

Multiple-input multiple-output (MIMO) wireless systems use atransmission scheme between a transmitter (e.g. a base station) and areceiver (e.g. a UE), where both transmitter and receiver are equippedwith multiple antennas. Some portions of wireless communications system100 may use beamforming. For example, base station 105 may have anantenna array with a number of rows and columns of antenna ports thatthe base station 105 may use for beamforming in its communication withUE 115. Signals may be transmitted multiple times in differentdirections (e.g., each transmission may be beamformed differently). AmmW receiver (e.g., a UE 115) may try multiple beams (e.g., antennasubarrays) while receiving the synchronization signals.

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support beamformingor MIMO operation. One or more base station antennas or antenna arraysmay be collocated at an antenna assembly, such as an antenna tower. Insome cases, antennas or antenna arrays associated with a base station105 may be located in diverse geographic locations. A base station 105may multiple use antennas or antenna arrays to conduct beamformingoperations for directional communications with a UE 115.

In some cases, wireless communications system 100 may be a packet-basednetwork that operate according to a layered protocol stack. In the userplane, communications at the bearer or Packet Data Convergence Protocol(PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may insome cases perform packet segmentation and reassembly to communicateover logical channels. A Medium Access Control (MAC) layer may performpriority handling and multiplexing of logical channels into transportchannels. The MAC layer may also use Hybrid ARQ (HARM) to provideretransmission at the MAC layer to improve link efficiency. In thecontrol plane, the Radio Resource Control (RRC) protocol layer mayprovide establishment, configuration, and maintenance of an RRCconnection between a UE 115 and a network device 105-c, network device105-b, or core network 130 supporting radio bearers for user plane data.At the Physical (PHY) layer, transport channels may be mapped tophysical channels.

Time intervals in LTE or NR may be expressed in multiples of a basictime unit (which may be a sampling period of T_(s)=1/30,720,000seconds). Time resources may be organized according to radio frames oflength of 10 ms (T_(f)=307200 T_(s)), which may be identified by asystem frame number (SFN) ranging from 0 to 1023. Each frame may includeten 1 ms subframes numbered from 0 to 9. A subframe may be furtherdivided into two 0.5 ms slots, each of which contains 6 or 7 OFDM symbolperiods (depending on the length of the cyclic prefix (CP) prepended toeach symbol). Excluding the cyclic prefix, each symbol contains 2048sample periods. In some cases the subframe may be the smallestscheduling unit, also known as a TTI. In other cases, a TTI may beshorter than a subframe or may be dynamically selected (e.g., in shortTTI bursts or in selected component carriers using short TTIs).

In some NR deployments, multiple different numerologies may beavailable, in which tone spacing for subcarriers may be increased ordecreased, with a corresponding decrease or increase in OFDM symbolperiods. For example, a 15 kHz tone spacing of legacy LTE may be used toprovide a slot with 7 OFDM symbol periods (for normal CP) with a slotduration of 0.5 ms, and thus would provide a radio frame with 20 slotsacross 10 subframes of a legacy 10 ms radio frame. Another numerologymay provide a 30 kHz tone spacing, which may reduce OFDM symbol durationby half relative to cases that have 15 kHz tone spacing, and wouldprovide a radio frame with 40 slots across a 10 ms time durationcorresponding to a legacy LTE frame. Further numerologies may also beavailable in NR systems, such as a 60 kHz tone spacing numerology having80 slots across a 10 ms time duration, a 120 kHz tone spacing numerologyhaving 160 slots across a 10 ms time duration, etc. In some cases, aslot index may be used to identify a slot within a radio frame, anddifferent numerologies may have different numbers of slots, and thusdifferent slot indices, within a radio frame.

For a 15 kHz tone spacing numerology, a resource element may consist ofone symbol period and one subcarrier (e.g., a 15 kHz frequency range). Aresource block may contain 12 consecutive subcarriers in the frequencydomain and, for a normal cyclic prefix in each OFDM symbol, 7consecutive OFDM symbols in the time domain (1 slot), or 84 resourceelements. Other numerologies may scale according to the tone spacing ofsubcarriers. The number of bits carried by each resource element maydepend on the modulation scheme (the configuration of symbols that maybe selected during each symbol period). Thus, the more resource blocksthat a UE receives and the higher the modulation scheme, the higher thedata rate may be.

Wireless communications system 100 may support operation on multiplecells or carriers, a feature which may be referred to as carrieraggregation (CA) or multi-carrier operation. A carrier may also bereferred to as a component carrier (CC), a layer, a channel, etc. Theterms “carrier,” “component carrier,” “cell,” and “channel” may be usedinterchangeably herein. A UE 115 may be configured with multipledownlink CCs and one or more uplink CCs for carrier aggregation. Carrieraggregation may be used with both FDD and TDD component carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including: wider bandwidth, shorter symbol duration, shortertransmission time interval (TTIs), and modified control channelconfiguration. In some cases, an eCC may be associated with a carrieraggregation configuration or a dual connectivity configuration (e.g.,when multiple serving cells have a suboptimal or non-ideal backhaullink). An eCC may also be configured for use in unlicensed spectrum orshared spectrum (where more than one operator is allowed to use thespectrum). An eCC characterized by wide bandwidth may include one ormore segments that may be utilized by UEs 115 that are not capable ofmonitoring the whole bandwidth or prefer to use a limited bandwidth(e.g., to conserve power).

In some cases, an eCC may utilize a different numerology, or symbolduration, than other CCs, which may include use of a reduced symbolduration as compared with symbol durations of the other CCs. A shortersymbol duration may be associated with increased subcarrier spacing, asdiscussed above, for different numerologies. A TTI in an eCC may consistof one or multiple symbols. In some cases, the TTI duration (that is,the number of symbols in a TTI) may be variable. A device, such as a UE115 or base station 105, utilizing eCCs may transmit wideband signals(e.g., 20, 40, 60, 80 Mhz, etc.) at reduced symbol durations (e.g.,16.67 microseconds). A TTI in eCC may consist of one or multiplesymbols.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ LTE License AssistedAccess (LTE-LAA) or LTE Unlicensed (LTE U) radio access technology or NRtechnology in an unlicensed band such as the 5 Ghz Industrial,Scientific, and Medical (ISM) band. When operating in unlicensed radiofrequency spectrum bands, wireless devices such as base stations 105 andUEs 115 may employ listen-before-talk (LBT) procedures to ensure thechannel is clear before transmitting data. In some cases, operations inunlicensed bands may be based on a carrier aggregation (CA)configuration in conjunction with component carriers (CCs) operating ina licensed band. Operations in unlicensed spectrum may include downlinktransmissions, uplink transmissions, or both. Duplexing in unlicensedspectrum may be based on frequency division duplexing (FDD), timedivision duplexing (TDD) or a combination of both.

In some cases, scrambling sequences may be used for different signalsthat are transmitted between base stations 105 and UEs. Variousdescribed techniques provide for identification of a scrambling sequenceused for a reference signal, a control signal, or a data signal that isindependent of a center frequency of a wireless communications system100 bandwidth. Such identification of scrambling sequences may allow fordemodulation of signals in which a synchronization channel does notshare a same center frequency as the wireless system bandwidth.

FIG. 2 illustrates an example of a wireless communications system 200for signal scrambling sequence techniques for wireless communications.Wireless communications system 200 includes base station 105-a and a UE115-a, that may be examples of aspects of a base station 105 or UE 115as described above with reference to FIG. 1. In the example of FIG. 2,the wireless communications system 200 may operate according to a radioaccess technology (RAT) such as a 5G or NR RAT, although techniquesdescribed herein may be applied to any RAT and to systems that mayconcurrently use two or more different RATs.

Base station 105-a may communicate with UE 115-a, and may receive uplinktransmissions from the UE 115-a and transmit downlink transmissions tothe UE 115-a over carrier 205. In some examples, base station 105-a mayallocate resources for communication with UEs over carrier 205, and insome cases may configure a synchronization channel 210 that may bemonitored by the UE 115-a. In some cases, a center frequency of thesynchronization channel 210 may be different than a center frequency ofthe system bandwidth used for communications between the UE 115-a andthe base station 105-a. The synchronization channel may includeinformation that UE 115-a may use to locate common control information,in some examples.

In some systems, control information, such as common controlinformation, UE-specific control information, or combinations thereof,may be transmitted in a physical downlink control channel (PDCCH)transmission. UE 115-a may use a reference signal transmission from thebase station 105-a, such as a cell-specific reference signal (CRS) toperform channel estimation, which may be used for demodulation of thePDCCH transmission. The reference signal transmission may be scrambled,and the scrambling value for each tone of the reference signal may be,in some cases, a function of cell ID, a subframe or slot index, and acenter frequency of the channel. Scrambling sequences for such signalsmay be designed to be not a function of system bandwidth. In somesystems, such as an NR or 5G system, different reference signals may beused for PDCCH demodulation, such as a demodulation reference signal(DMRS), for demodulation of common control information, UE-specificcontrol information, or combinations thereof. In such cases, scramblingsequences for the different reference signals may be defined to allow UE115-a to perform channel estimation using the reference signal.Additionally, various other parameters that may be used for scramblingsequence determination (e.g., cell ID, subframe or slot index, centerfrequency, etc.) may be identified for NR systems that may havedifferent numerologies and therefore different subframe or slot indexes,synchronization channels that are not centered on a system bandwidth, orother variable parameters.

Furthermore, in some NR systems, common control information may betransmitted in control resource sets (subbands) that may not occupy afull wideband signal. In some cases, the synchronization channel 210 maycontain information to point the UE 115-a to the common control resourceset, and the UE 115-a can be redirected to a UE-specific controlresource set after receiving the common control resource set. Asindicated above, in some cases the synchronization channel 210 also mayhave a different center frequency than a center frequency of the systembandwidth. The common control resource set may also be configured todifferent locations within the system bandwidth as well, which may notnecessarily be centered in the system bandwidth. Various techniquesprovided herein may be used by UE 115-a to decode, for example, a PDCCHin a common control resource set, by providing scrambling sequences forsignals that are used for channel estimation and demodulation.

FIG. 3 illustrates an example of wireless resources 300 for asynchronization channel relative to a system bandwidth, in accordancewith aspects of the present disclosure. The wireless resources 300 maybe used, for example, in communications between a UE and a base stationsuch as discussed above with respect to FIGS. 1 and 2.

In this example, center frequency 305 of a maximum system bandwidth 310may also be the center frequency of a system bandwidth 315 being usedfor current transmissions and for a synchronization channel 320. Thesynchronization channel 320 may contain synchronization signals, such asa primary synchronization signal (PSS) and a secondary synchronizationsignal (SSS), which may enable synchronization on a subframe level andallow for identification of a physical layer identity and cell ID, whichmay be used to identify a location of one or more reference signals forchannel estimation. As the synchronization signal is centered in thesystem bandwidth 315, a UE that identifies the synchronization signalmay effectively identify the center of the channel as center frequency305, according to techniques such as used in legacy LTE systems. Incases where such a configuration is used in NR systems, a base stationmay indicate that legacy LTE synchronization sequences may be used. Insuch cases, the scrambling of a signal, such as a reference signal foruse in decoding a control channel transmissions, may be defined for themaximum system bandwidth. The lower end 325 of the maximum systembandwidth 310 may be identified from the center frequency 305 of thechannel and may be used as a reference resource element (RE) forgenerating a scrambling sequence. A random number generator may beinitiated with a seed as a function of the cell ID and subframe index togenerate a series of pseudo-random numbers that may be sequentiallyfilled for the scrambled signal REs, starting from the reference RE inthe upwards direction to the upper end 330 of the maximum systembandwidth 310, with only the REs within the system bandwidth 315 beingused. While the center frequency 305 of FIG. 3 is common across thesynchronization channel 320, maximum system bandwidth 310, and systembandwidth 315, other examples may not have such a common centerfrequency.

FIG. 4 illustrates another example of wireless resources 400 for signalscrambling sequence techniques for wireless communications, inaccordance with aspects of the present disclosure. The wirelessresources 400 may be used, for example, in communications between a UEand a base station such as discussed above with respect to FIGS. 1 and2.

In this example, center frequency 405 of a maximum system bandwidth 410may be different than a synchronization center frequency 420 of asynchronization channel 415. Furthermore, a set of common controlresources 425 may be offset from the synchronization channel 415. Insuch cases, a receiver, such as a UE, may not be able to identify systembandwidth information and center frequency information from thesynchronization channel 415. In some examples, the synchronizationchannel 415 may include an indication of a location of the commoncontrol resources 425, and when a receiver picks up synchronizationchannel 415, it may identify a location of the common control resources425. In such cases, the receiver may still be unaware of a relativelocation of the synchronization channel 415 and common control resources425 within the system bandwidth 410.

In some examples, scrambling sequences for a signal that may be used todemodulate the common control resources 425 may be defined such that thescrambling sequence is independent from the center frequency 405 of thesystem bandwidth 410. In some examples, such a scrambling sequence for asignal (e.g., a DMRS), may be defined to depend on the synchronizationcenter frequency 420 of the synchronization channel 415, but notdepending on the channel center frequency 405. In such cases, after a UEhas identified the synchronization channel 415, and knows thesynchronization center frequency 420, it may determine the scramblingsequence for the signal to be used to demodulate the common controlresources 425 (e.g., a scrambling sequence for a DMRS).

In other examples, a scrambling sequence for a signal (e.g., a DMRS),may be defined to be independent from synchronization center frequency420 as well. In such cases, a receiver, such as a UE, may identify thescrambling sequence for tones within the common control resources 425,only as a function of cell ID and slot index. In some examples, the slotindex may be linked to a specific reference numerology due to multiplenumerologies supported in NR as discussed above. Such a referencenumerology may correspond to a 15 kHz tone spacing, or multiplesthereof, in some examples. In such a manner, when the receiver knowswhere the set of common control resources 425 is, it may identify how todescramble the resources before decoding, for example, a minimum systeminformation block (MSIB) from a transmitter such as a base station.While various examples are described herein with reference to a DMRSscrambling sequence that may be used to demodulate common controlinformation, such scrambling sequence techniques may be used for anyreference signals, control signals, or data signals that may havescrambling sequences applied thereto.

As indicated above, in some examples a scrambling sequence may beidentified based on synchronization center frequency 420. In some cases,the synchronization center frequency 420 may be identified as one pointon a raster of potential synchronization center frequencies. Thus areceiver, such as a UE, after identifying the synchronization channel415 may identify the associated point on the raster as thesynchronization center frequency 420, which may be different from thechannel center frequency 405. The scrambling sequence for a referencesignal (e.g., a DMRS) for PDCCH demodulation may be defined with respectto the synchronization center frequency 420. In such cases, a randomnumber generator may be initiated with a seed as a function of the cellID and subframe index that are determined from the synchronizationchannel 415. A RE associated with the synchronization center frequency420 may be defined as the reference RE, which may be a RE that containsthe synchronization center frequency 420 or a RE with a known constantoffset from the synchronization center frequency 420. For example, insome cases, the known constant offset may be an offset from the edge ofsynchronization channel 415 or the synchronization center frequency 420.In some examples, the known constant offset may be an offset from theedge of common control resources 425, center frequency 405, or thecenter of common control resources 425. The known constant offset may bereceived in some additional signaling (e.g., synchronization channel 415or common control resources 425). For example, the known constant offsetmay be determined based on a PBCH, or a RMSI. The random numbergenerator may be used to generate a sequence of pseudo-random numbersthat may be sequentially filled in the reference signal REs startingfrom the reference RE in an upward direction. In some cases, thegenerated sequence may wrap around at another fixed known offset incases where reference signal REs may be located at frequencies belowthat of the reference RE. Such a wrap around may not be necessary incases where the reference RE is defined to be low enough that there willnot be any reference signal REs at lower frequencies in the samechannel. In some examples, the scrambling sequence may start from thesynchronization center frequency 420 reference RE and reference signalREs may be filled in both upwards and downwards directions, instead ofupwards only.

In some cases, multiple component carriers may be present in a system,and a receiver, such as a UE, may need to identify a synchronizationchannel center frequency for different carriers in order to descramble areference signal of the other carrier. In some examples, a receiver maybe signaled to monitor a control resource set of another carrier, andmay be provided with the center of the synchronization channel of theother carrier, which may allow for generation of the scrambling sequenceat the other carrier. In other examples, multiple synchronizationsignals may be transmitted at different points on the synchronizationraster. In such cases, a synchronization signal transmitter, such as abase station, may provide a common control resource set pointed fromrespective synchronization signals and the scrambling sequence may bedetermined as discussed above. For other control resource sets, atransmitter may provide an indication of a particular synchronizationsignal to use in order to generate a scrambling sequence, or mayindicate that a different scrambling sequence generation may be used forsuch other control resource sets.

FIG. 5 illustrates another example of wireless resources 500 for signalscrambling sequence techniques for wireless communications. The wirelessresources 500 may be used, for example, in communications between a UEand a base station such as discussed above with respect to FIGS. 1 and2.

In this example, center frequency 505 of a maximum system bandwidth 515may be different than a synchronization center frequency 520 of asynchronization channel 525. The synchronization center frequency 520may be one point of a synchronization raster 510 that may provide anumber of available synchronization center frequencies. In this example,a reference RE 530 may be defined. Furthermore, a set of common controlresources 535 may be offset from the synchronization channel 525.Similarly as discussed above, a receiver, such as a UE, may not be ableto identify system bandwidth information and center frequencyinformation from the synchronization channel 525. In some examples, thesynchronization channel 525 may include an indication of a location ofthe common control resources 535, and when a receiver picks upsynchronization channel 525, it may identify a location of the commoncontrol resources 535. In such cases, the receiver may still be unawareof a relative location of the synchronization channel 525 and commoncontrol resources 535 within the system bandwidth 515.

In this example, the synchronization channel 525 may be centered on oneof the points on the synchronization raster 510. After a receiveridentifies the synchronization channel 525, it may identify thesynchronization center frequency 520, which may be different than thechannel center frequency 505. In the example of FIG. 5, a scramblingsequence for a reference signal (e.g., DMRS) for control channeldemodulation may be defined with respect to an absolute reference RE530. In such cases, the random number generator may be initiated with aseed as a function of the cell ID and subframe index, identified fromthe synchronization channel 525, and the random numbers generated andsequentially filled in the reference signal REs starting from thereference RE 530 in upward direction. In some cases, only referencesignal REs within the system bandwidth 515 are used for generating thescrambling sequence.

In some cases, the reference RE 530 may be defined as a point in thesynchronization raster 510 index. In some cases, the reference RE 530may be defined such that it is relatively close to the set of commoncontrol resources 535, which may provide relatively shorter scramblingsequences to reach and cover the common control resources 535, and mayhelp to reduce the number of times the random number generator is to beclocked. For example, it the reference RE 530 is at f0 and the carrierfor the set of common control resources 535 is centered at f1, and f0and f1 are relatively far apart, then the random number generator mayneed to be clocked a number of times in which the output is unused.

As indicated above, the seed for a random number generator thatgenerates the scrambling sequence may be a function of cell ID and slotindex (time). In cases where a number of different numerologies may beavailable, such as different available numerologies in NR, a numerologyindex may be included in the function to determine the random seed.Furthermore, if extended CP (ECP) is supported in addition to normal CP(NCP), an NCP or ECP flag may be used in the function to generate theseed as well.

FIG. 6 illustrates another example of wireless resources 600 for signalscrambling sequence techniques for wireless communications, inaccordance with various aspects of the present disclosure. The wirelessresources 600 may be used, for example, in communications between a UEand a base station such as discussed above with respect to FIGS. 1 and2.

In this example, center frequency 605 of a system bandwidth 615 may onceagain be different than a synchronization center frequency of asynchronization channel. The synchronization center frequency may be onepoint of a synchronization raster 610 that may provide a number ofavailable synchronization center frequencies. In this example, a numberof different available reference REs 620 may be defined that may be usedto provide a number of cycles 625 of reference signal scramblingsequences.

In the example of FIG. 6, when the synchronization raster 610 isdefined, a number of reference RE 620 reference points may beestablished. Each point in the synchronization raster 610 may have araster frequency index (like a channel index) s. In some examples, areference RE 620 may be identified as a tone corresponding to thesynchronization raster frequency with s mod X=0, in which X is aspecified integer parameter, X≥1. Alternatively, one or more of thereference REs 620 may be defined as a fixed offset from thesynchronization raster frequency with s mod X=0. For example, the fixedoffset may be a known constant offset, and may be an offset from asynchronization signal corresponding to synchronization raster 610, orfrom a common control signal. The known constant offset may be receivedin some additional signaling (e.g., the synchronization signal or thecommon control signal). For example, the known constant offset may bedetermined based on a physical broadcast channel (PBCH), or remainingminimum system information (RMSI). The random number generator thatgenerates the scrambling sequence may start from the correspondingreference RE 620 and fill the reference signal REs in a upwarddirection. The sequence generator may be reset to the initial seed whenreaching the next reference RE 620, and thus the scrambling sequence forthe reference signal transmission may have a periodic structure with anumber of cycles 625 of scrambling sequences.

The selection of X in such examples will determine a length of theperiod of each cycle 625 of scrambling sequences. In some cases, thelength of the period may be selected to be long enough to providerelatively small impact on a peak to average power ratio (PAPR) of thereference signal and yet be short enough to provide a relatively shortscrambling sequence which may provide some memory and processingresources savings. In some cases, if the reference signal is to betransmitted in a downlink transmission from a base station, the PAPR maynot be as critical than if the reference signal is transmitted in anuplink transmission from a UE. Thus, in some cases, the value of X maybe selected based on a transmitter that is to transmit the scrambledreference signal, control signal, or data signal. In one example, thespacing of points in the synchronization raster 610 may be 1.8 MHz, andthe value of X may be set at X=10, which may provide that there is not arepetition in the scrambling sequence if the system bandwidth is within18 MHz. In another example, the spacing of points in the synchronizationraster 610 may be 1.8 MHz, and the value of X may be set at X=2, whichprovides that there will be five repetitions in a system bandwidth of 18MHz. Such a periodic sequence design may be used in cases where thereare multiple synchronization signals on different synchronization rasterpoints. In some cases, a UE may be signaled to monitor a controlresource set of another carrier, and would not need to know thesynchronization signal center frequency of the other carrier.

FIG. 7 illustrates an example of a process flow 700 for signalscrambling sequence techniques for wireless communications, inaccordance with various aspects of the present disclosure. Process flow700 may include a base station 105-b and a UE 115-b, that may beexamples of the corresponding devices described with reference to FIGS.1 and 2.

Base station 105-b may transmit a synchronization channel 705 to the UE115-b. The synchronization channel may include, for example, PSS and SSStransmissions, as well as an indication of a location of a commoncontrol resource set within a system bandwidth. In some cases, thecommon control resource set may be offset from the synchronizationchannel. In some cases, a center frequency of the synchronizationchannel may be different than a center frequency of the system bandwidthfor communications between the base station 105-b and UE 115-b.

At block 710, the UE 115-b may identify a location on the common controlresource set. The location on the common control resource set may beidentified, for example, by a pointer contained in the synchronizationchannel that may indicate the location of the common control resourceset. In some cases, such a pointer may provide a relative location ofthe common control resource set that is relative to a center frequencyof the synchronization channel. In some cases, such a pointer may have avalue that is mapped to a particular offset, for example.

At block 715, the UE 115-b may identify a scrambling sequence for thecommon control resource set. In some cases, the scrambling sequence maybe used to scramble a reference signal, and the reference signal may beused for channel estimation to demodulate the information in the commoncontrol resource set, such as PDCCH transmissions contained in thecommon control resource set. The scrambling sequence may be identifiedbased at least in part on the center frequency of the synchronizationchannel, in some examples such as discussed above with reference to FIG.4. In some examples, the scrambling sequence may be identifiedindependently of a center frequency of the synchronization channel or acenter frequency of the system bandwidth, such as discussed above withreference to FIGS. 5 and 6.

At block 720, the base station 105-b may generate common controlinformation for transmission in the common control resources. The commoncontrol information may include, for example, random access informationand system parameters that may be used to establish a connection betweenthe base station 105-b and UE 115-b. The common control information maybe formatted into the set of common control resources that are indicatedin the synchronization channel, and transmitted in downlink transmission725 to the UE 115-b.

The UE 115-b may, at block 730, descramble a reference signal of thecommon control information. The UE 115-b may descramble the referencesignal according to the identified scrambling sequence for the referencesignal. A channel estimation may be performed based on the descrambledreference signal, which may be used to demodulate and decode the commoncontrol information, as indicated at block 735.

FIG. 8 shows a block diagram 800 of a wireless device 805 that supportssignal scrambling sequence techniques for wireless communications inaccordance with various aspects of the present disclosure. Wirelessdevice 805 may be an example of aspects of a user equipment (UE) 115 orbase station 105 as described with reference to FIG. 1. Wireless device805 may include receiver 810, scrambling sequence manager 815, andtransmitter 820. Wireless device 805 may also include a processor. Eachof these components may be in communication with one another (e.g., viaone or more buses).

Receiver 810 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to signalscrambling sequence techniques for wireless communications, etc.).Information may be passed on to other components of the device. Thereceiver 810 may be an example of aspects of the transceiver 1135described with reference to FIG. 11.

Scrambling sequence manager 815 may be an example of aspects of thescrambling sequence manager 1115 described with reference to FIG. 11.

Scrambling sequence manager 815 and/or at least some of its varioussub-components may be implemented in hardware, software executed by aprocessor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the scramblingsequence manager 815 and/or at least some of its various sub-componentsmay be executed by a general-purpose processor, a digital signalprocessor (DSP), an application-specific integrated circuit (ASIC), anfield-programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure. The scrambling sequence manager 815 and/or at leastsome of its various sub-components may be physically located at variouspositions, including being distributed such that portions of functionsare implemented at different physical locations by one or more physicaldevices. In some examples, scrambling sequence manager 815 and/or atleast some of its various sub-components may be a separate and distinctcomponent in accordance with various aspects of the present disclosure.In other examples, scrambling sequence manager 815 and/or at least someof its various sub-components may be combined with one or more otherhardware components, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with various aspects of the present disclosure.

Scrambling sequence manager 815 may identify a synchronization channelcontaining location information for a common control resource set withina system bandwidth, determine a location of the common control resourceset within the system bandwidth based on the location information,determine a scrambling sequence for one or more of a reference signal, acontrol signal, or a data signal, for use in demodulating the commoncontrol resource set, and process one or more of the reference signal,the control signal, or the data signal, based on the scramblingsequence.

Transmitter 820 may transmit signals generated by other components ofthe device. In some examples, the transmitter 820 may be collocated witha receiver 810 in a transceiver module. For example, the transmitter 820may be an example of aspects of the transceiver 1135 described withreference to FIG. 11. The transmitter 820 may include a single antenna,or it may include a set of antennas.

FIG. 9 shows a block diagram 900 of a wireless device 905 that supportssignal scrambling sequence techniques for wireless communications inaccordance with various aspects of the present disclosure. Wirelessdevice 905 may be an example of aspects of a wireless device 805 or a UE115 or base station 105 as described with reference to FIGS. 1 and 8.Wireless device 905 may include receiver 910, scrambling sequencemanager 915, and transmitter 920. Wireless device 905 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

Receiver 910 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to signalscrambling sequence techniques for wireless communications, etc.).Information may be passed on to other components of the device. Thereceiver 910 may be an example of aspects of the transceiver 1135described with reference to FIG. 11.

Scrambling sequence manager 915 may be an example of aspects of thescrambling sequence manager 1115 described with reference to FIG. 11.Scrambling sequence manager 915 may also include synchronization channelcomponent 925, common control resource component 930, scramblingsequence identification component 935, and signal processing component940.

Synchronization channel component 925 may identify a synchronizationchannel containing location information for a common control resourceset within a system bandwidth. In some cases, the center frequency ofthe synchronization channel is different than a center frequency of thesystem bandwidth.

Common control resource component 930 may determine a location of thecommon control resource set within the system bandwidth based on thelocation information. In some cases, the common control resource set maybe transmitted on a second component carrier that is different than afirst component carrier used to transmit the synchronization channel.

Scrambling sequence identification component 935 may determine ascrambling sequence for one or more of a reference signal, a controlsignal, or a data signal, for use in demodulating the common controlresource set. In some cases, scrambling sequence identificationcomponent 935 may determine the scrambling sequence for one or more ofthe reference signal, the control signal, or the data signal, based on acell ID and slot or subframe index of the signal. In some cases,scrambling sequence identification component 935 may identify a centerfrequency of the synchronization channel, and the scrambling sequencefor one or more of the reference signal, the control signal, or the datasignal, may be determined based on the center frequency of thesynchronization channel. In some cases, scrambling sequenceidentification component 935 may identify a center frequency of a secondsynchronization channel transmitted on the second component carrier, anddetermine the scrambling sequence for one or more of the referencesignal, the control signal, or the data signal, for use in demodulatingthe common control resource set based on the center frequency of thesecond synchronization channel.

In some cases, scrambling sequence identification component 935 mayidentify a reference RE location within the system bandwidth, andgenerate the scrambling sequence based on the cell ID, the slot orsubframe index, and the reference RE location. In some examples,identifying the reference RE location may comprise identifying aconstant fixed offset based at least in part on at least one of aphysical broadcast channel (PBCH) or remaining minimum systeminformation (RMSI). In some cases, the scrambling sequence for one ormore of the reference signal, the control signal, or the data signal, isdetermined independently of a center frequency of the synchronizationchannel or a center frequency of the system bandwidth. In some cases,the processing one or more of the reference signal, the control signal,or the data signal, includes identifying a cell ID and a slot orsubframe index associated with the common control resource set,identifying a center frequency of the synchronization channel,generating the scrambling sequence based on the cell ID, the slot orsubframe index, and the center frequency of the synchronization channel,and applying the scrambling sequence to a signal pattern of one or moreof the reference signal, the control signal, or the data signal. In somecases, the processing one or more of the reference signal, the controlsignal, or the data signal, further includes identifying a reference REassociated with a received signal, and filling the scrambling sequencefor REs of one or more of the reference signal, the control signal, orthe data signal, REs starting at the reference RE based on the generatedscrambling sequence. In some examples, identifying the reference RE maycomprise identifying a constant fixed offset based at least in part onat least one of a PBCH or RMSI.

Signal processing component 940 may apply the scrambling sequence to areference signal REs starting at the reference RE location based on thegenerated scrambling sequence and process one or more of the referencesignal, the control signal, or the data signal, based on the scramblingsequence.

Transmitter 920 may transmit signals generated by other components ofthe device. In some examples, the transmitter 920 may be collocated witha receiver 910 in a transceiver module. For example, the transmitter 920may be an example of aspects of the transceiver 1135 described withreference to FIG. 11. The transmitter 920 may include a single antenna,or it may include a set of antennas.

FIG. 10 shows a block diagram 1000 of a scrambling sequence manager 1015that supports signal scrambling sequence techniques for wirelesscommunications in accordance with various aspects of the presentdisclosure. The scrambling sequence manager 1015 may be an example ofaspects of a scrambling sequence manager 815, a scrambling sequencemanager 915, or a scrambling sequence manager 1115 described withreference to FIGS. 8, 9, and 11. The scrambling sequence manager 1015may include synchronization channel component 1020, common controlresource component 1025, scrambling sequence identification component1030, signal processing component 1035, slot/subframe index component1040, and raster component 1045. Each of these modules may communicate,directly or indirectly, with one another (e.g., via one or more buses).

Synchronization channel component 1020 may identify a synchronizationchannel containing location information for a common control resourceset within a system bandwidth. In some cases, the center frequency ofthe synchronization channel is different than a center frequency of thesystem bandwidth.

Common control resource component 1025 may determine a location of thecommon control resource set within the system bandwidth based on thelocation information and identify that the common control resource setis transmitted on a second carrier that is different than a firstcarrier used to transmit the synchronization channel.

Scrambling sequence identification component 1030 may determine ascrambling sequence for one or more of a reference signal, a controlsignal, or a data signal, for use in demodulating the common controlresource set. In some cases, scrambling sequence identificationcomponent 1030 may determine the scrambling sequence for one or more ofthe reference signal, the control signal, or the data signal, based on acell ID and slot or subframe index of the signal. In some cases,scrambling sequence identification component 1030 may identify a centerfrequency of the synchronization channel, and the scrambling sequencefor one or more of the reference signal, the control signal, or the datasignal, may be determined based on the center frequency of thesynchronization channel. In some cases, scrambling sequenceidentification component 1030 may identify a center frequency of asecond synchronization channel transmitted on the second componentcarrier, and determine the scrambling sequence for one or more of thereference signal, the control signal, or the data signal, for use indemodulating the common control resource set based on the centerfrequency of the second synchronization channel.

In some cases, scrambling sequence identification component 1030 mayidentify a reference RE location within the system bandwidth, andgenerate the scrambling sequence based on the cell ID, the slot orsubframe index, and the reference RE location. In some examples,identifying the reference RE location may comprise identifying aconstant fixed offset based at least in part on at least one of a PBCHor RMSI. In some cases, the scrambling sequence for one or more of thereference signal, the control signal, or the data signal, is determinedindependently of a center frequency of the synchronization channel or acenter frequency of the system bandwidth. In some cases, the processingone or more of the reference signal, the control signal, or the datasignal, includes identifying a cell ID and a slot or subframe indexassociated with the common control resource set, identifying a centerfrequency of the synchronization channel, generating the scramblingsequence based on the cell ID, the slot or subframe index, and thecenter frequency of the synchronization channel, and applying thescrambling sequence to a signal pattern of one or more of the referencesignal, the control signal, or the data signal. In some cases, theprocessing one or more of the reference signal, the control signal, orthe data signal, further includes identifying a reference RE associatedwith a received signal, and filling the scrambling sequence for REs ofone or more of the reference signal, the control signal, or the datasignal, REs starting at the reference RE based on the generatedscrambling sequence. In some examples, identifying the reference RE maycomprise identifying a constant fixed offset based at least in part onat least one of a PB CH or RMSI.

Signal processing component 1035 may apply the scrambling sequence to areference signal REs starting at the reference RE location based on thegenerated scrambling sequence and process one or more of the referencesignal, the control signal, or the data signal, based on the scramblingsequence.

Slot/subframe index component 1040 may determine a cell ID and a slot orsubframe index for the common control resource set. In some cases, theslot or subframe index is based on a reference numerology of a set ofavailable numerologies for wireless transmissions within the systembandwidth. In some cases, the reference numerology corresponds to a 15kHz tone spacing or multiples thereof.

Raster component 1045 may identify a raster of synchronization channelcenter frequencies within the system bandwidth, identify a centerfrequency of the synchronization channel as one of the synchronizationchannel center frequencies on the raster of synchronization channelcenter frequencies. In some cases, a first synchronization channelcenter frequency may be identified as a reference RE location within thesystem bandwidth. In some cases, the first synchronization channelcenter frequency is selected based on an index of the raster ofsynchronization channel center frequencies and a parameter thatidentifies a scrambling sequence or a length of the scrambling sequence.

FIG. 11 shows a diagram of a system 1100 including a device 1105 thatsupports signal scrambling sequence techniques for wirelesscommunications in accordance with various aspects of the presentdisclosure. Device 1105 may be an example of or include the componentsof wireless device 805, wireless device 905, or a UE 115 as describedabove, e.g., with reference to FIGS. 1, 8 and 9. Device 1105 may includecomponents for bi-directional voice and data communications includingcomponents for transmitting and receiving communications, including UEscrambling sequence manager 1115, processor 1120, memory 1125, software1130, transceiver 1135, antenna 1140, and I/O controller 1145. Thesecomponents may be in electronic communication via one or more busses(e.g., bus 1110). Device 1105 may communicate wirelessly with one ormore base stations 105.

Processor 1120 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a central processing unit (CPU), amicrocontroller, an ASIC, an FPGA, a programmable logic device, adiscrete gate or transistor logic component, a discrete hardwarecomponent, or any combination thereof). In some cases, processor 1120may be configured to operate a memory array using a memory controller.In other cases, a memory controller may be integrated into processor1120. Processor 1120 may be configured to execute computer-readableinstructions stored in a memory to perform various functions (e.g.,functions or tasks supporting signal scrambling sequence techniques forwireless communications).

Memory 1125 may include random access memory (RAM) and read only memory(ROM). The memory 1125 may store computer-readable, computer-executablesoftware 1130 including instructions that, when executed, cause theprocessor to perform various functions described herein. In some cases,the memory 1125 may contain, among other things, a basic input/outputsystem (BIOS) which may control basic hardware and/or software operationsuch as the interaction with peripheral components or devices.

Software 1130 may include code to implement aspects of the presentdisclosure, including code to support signal scrambling sequencetechniques for wireless communications. Software 1130 may be stored in anon-transitory computer-readable medium such as system memory or othermemory. In some cases, the software 1130 may not be directly executableby the processor but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

Transceiver 1135 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1135 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1135 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1140.However, in some cases the device may have more than one antenna 1140,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

I/O controller 1145 may manage input and output signals for device 1105.I/O controller 1145 may also manage peripherals not integrated intodevice 1105. In some cases, I/O controller 1145 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 1145 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 1145 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 1145 may be implemented as part of aprocessor. In some cases, a user may interact with device 1105 via I/Ocontroller 1145 or via hardware components controlled by I/O controller1145.

FIG. 12 shows a diagram of a system 1200 including a device 1205 thatsupports signal scrambling sequence techniques for wirelesscommunications in accordance with various aspects of the presentdisclosure. Device 1205 may be an example of or include the componentsof wireless device 905, wireless device 1005, or a base station 105 asdescribed above, e.g., with reference to FIGS. 1, 9 and 10. Device 1205may include components for bi-directional voice and data communicationsincluding components for transmitting and receiving communications,including base station scrambling sequence manager 1215, processor 1220,memory 1225, software 1230, transceiver 1235, antenna 1240, networkcommunications manager 1245, and base station communications manager1250. These components may be in electronic communication via one ormore busses (e.g., bus 1210). Device 1205 may communicate wirelesslywith one or more UEs 115.

Processor 1220 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 1220 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into processor 1220. Processor 1220 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting signal scramblingsequence techniques for wireless communications).

Memory 1225 may include RAM and ROM. The memory 1225 may storecomputer-readable, computer-executable software 1230 includinginstructions that, when executed, cause the processor to perform variousfunctions described herein. In some cases, the memory 1225 may contain,among other things, a BIOS which may control basic hardware and/orsoftware operation such as the interaction with peripheral components ordevices.

Software 1230 may include code to implement aspects of the presentdisclosure, including code to support signal scrambling sequencetechniques for wireless communications. Software 1230 may be stored in anon-transitory computer-readable medium such as system memory or othermemory. In some cases, the software 1230 may not be directly executableby the processor but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

Transceiver 1235 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1235 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1235 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1240.However, in some cases the device may have more than one antenna 1240,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

Network communications manager 1245 may manage communications with thecore network (e.g., via one or more wired backhaul links). For example,the network communications manager 1245 may manage the transfer of datacommunications for client devices, such as one or more UEs 115.

Base station communications manager 1250 may manage communications withother base station 105, and may include a controller or scheduler forcontrolling communications with UEs 115 in cooperation with other basestations 105. For example, the base station communications manager 1250may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, base station communications manager 1250may provide an X2 interface within an Long Term Evolution (LTE)/LTE-Awireless communication network technology to provide communicationbetween base stations 105.

FIG. 13 shows a flowchart illustrating a method 1300 for signalscrambling sequence techniques for wireless communications in accordancewith various aspects of the present disclosure. The operations of method1300 may be implemented by a UE 115 or base station 105 or itscomponents as described herein. For example, the operations of method1300 may be performed by a scrambling sequence manager as described withreference to FIGS. 8 through 10. In some examples, a UE 115 or basestation 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the UE 115 or base station 105 mayperform aspects of the functions described below using special-purposehardware.

At block 1305 the UE 115 or base station 105 may identify asynchronization channel containing location information for a commoncontrol resource set within a system bandwidth. The operations of block1305 may be performed according to the methods described with referenceto FIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1305 may be performed by a synchronization channel component asdescribed with reference to FIGS. 8 through 10.

At block 1310 the UE 115 or base station 105 may determine a location ofthe common control resource set within the system bandwidth based atleast in part on the location information. The operations of block 1310may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1310 may be performed by a common control resource component asdescribed with reference to FIGS. 8 through 10.

At block 1315 the UE 115 or base station 105 may determine a scramblingsequence for one or more of a reference signal, a control signal, or adata signal, for use in demodulating the common control resource set.The operations of block 1315 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1315 may be performed by a scramblingsequence identification component as described with reference to FIGS. 8through 10.

At block 1320 the UE 115 or base station 105 may process one or more ofthe reference signal, the control signal, or the data signal, based atleast in part on the scrambling sequence. The operations of block 1320may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1320 may be performed by a signal processing component asdescribed with reference to FIGS. 8 through 10.

FIG. 14 shows a flowchart illustrating a method 1400 for signalscrambling sequence techniques for wireless communications in accordancewith various aspects of the present disclosure. The operations of method1400 may be implemented by a UE 115 or base station 105 or itscomponents as described herein. For example, the operations of method1400 may be performed by a scrambling sequence manager as described withreference to FIGS. 8 through 10. In some examples, a UE 115 or basestation 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the UE 115 or base station 105 mayperform aspects of the functions described below using special-purposehardware.

At block 1405 the UE 115 or base station 105 may identify a centerfrequency of a synchronization channel containing location informationfor a common control resource set within a system bandwidth. Theoperations of block 1405 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1405 may be performed by asynchronization channel component as described with reference to FIGS. 8through 10.

At block 1410 the UE 115 or base station 105 may determine a location ofthe common control resource set within the system bandwidth based atleast in part on the location information. The operations of block 1410may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1410 may be performed by a common control resource component asdescribed with reference to FIGS. 8 through 10.

At block 1415 the UE 115 or base station 105 may determine a scramblingsequence for one or more of a reference signal, a control signal, or adata signal, for use in demodulating the common control resource setbased on the center frequency of the synchronization channel. Theoperations of block 1415 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1415 may be performed by a scramblingsequence identification component as described with reference to FIGS. 8through 10.

At block 1420 the UE 115 or base station 105 may process one or more ofthe reference signal, the control signal, or the data signal, based atleast in part on the scrambling sequence. The operations of block 1420may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1420 may be performed by a signal processing component asdescribed with reference to FIGS. 8 through 10.

FIG. 15 shows a flowchart illustrating a method 1500 for signalscrambling sequence techniques for wireless communications in accordancewith various aspects of the present disclosure. The operations of method1500 may be implemented by a UE 115 or base station 105 or itscomponents as described herein. For example, the operations of method1500 may be performed by a scrambling sequence manager as described withreference to FIGS. 8 through 10. In some examples, a UE 115 or basestation 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the UE 115 or base station 105 mayperform aspects of the functions described below using special-purposehardware.

At block 1505 the UE 115 or base station 105 may identify asynchronization channel containing location information for a commoncontrol resource set within a system bandwidth. The operations of block1505 may be performed according to the methods described with referenceto FIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1505 may be performed by a synchronization channel component asdescribed with reference to FIGS. 8 through 10.

At block 1510 the UE 115 or base station 105 may determine a location ofthe common control resource set within the system bandwidth based atleast in part on the location information. The operations of block 1510may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1510 may be performed by a common control resource component asdescribed with reference to FIGS. 8 through 10.

At block 1515 the UE 115 or base station 105 may determine a cell ID anda slot or subframe index for the common control resource set. Theoperations of block 1515 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1515 may be performed by aslot/subframe index component as described with reference to FIGS. 8through 10.

At block 1520 the UE 115 or base station 105 may determine thescrambling sequence for one or more of the reference signal, the controlsignal, or the data signal, based on the cell ID and slot or subframeindex. The operations of block 1520 may be performed according to themethods described with reference to FIGS. 1 through 7. In certainexamples, aspects of the operations of block 1520 may be performed by ascrambling sequence identification component as described with referenceto FIGS. 8 through 10.

At block 1525 the UE 115 or base station 105 may process one or more ofthe reference signal, the control signal, or the data signal, based atleast in part on the scrambling sequence. The operations of block 1525may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1525 may be performed by a signal processing component asdescribed with reference to FIGS. 8 through 10.

FIG. 16 shows a flowchart illustrating a method 1600 for signalscrambling sequence techniques for wireless communications in accordancewith various aspects of the present disclosure. The operations of method1600 may be implemented by a UE 115 or base station 105 or itscomponents as described herein. For example, the operations of method1600 may be performed by a scrambling sequence manager as described withreference to FIGS. 8 through 10. In some examples, a UE 115 or basestation 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the UE 115 or base station 105 mayperform aspects of the functions described below using special-purposehardware.

At block 1605 the UE 115 or base station 105 may identify asynchronization channel containing location information for a commoncontrol resource set within a system bandwidth. The operations of block1605 may be performed according to the methods described with referenceto FIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1605 may be performed by a synchronization channel component asdescribed with reference to FIGS. 8 through 10.

At block 1610 the UE 115 or base station 105 may identify a raster ofsynchronization channel center frequencies within the system bandwidth.The operations of block 1610 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1610 may be performed by a rastercomponent as described with reference to FIGS. 8 through 10.

At block 1615 the UE 115 or base station 105 may identify a centerfrequency of the synchronization channel as one of the synchronizationchannel center frequencies on the raster of synchronization channelcenter frequencies. The operations of block 1615 may be performedaccording to the methods described with reference to FIGS. 1 through 7.In certain examples, aspects of the operations of block 1615 may beperformed by a raster component as described with reference to FIGS. 8through 10.

At block 1620 the UE 115 or base station 105 may determine a location ofthe common control resource set within the system bandwidth based atleast in part on the location information. The operations of block 1620may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1620 may be performed by a common control resource component asdescribed with reference to FIGS. 8 through 10.

At block 1625 the UE 115 or base station 105 may determine a scramblingsequence for one or more of a reference signal, a control signal, or adata signal, for use in demodulating the common control resource set.The operations of block 1625 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1625 may be performed by a scramblingsequence identification component as described with reference to FIGS. 8through 10.

At block 1630 the UE 115 or base station 105 may process one or more ofthe reference signal, the control signal, or the data signal, based atleast in part on the scrambling sequence. The operations of block 1630may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1630 may be performed by a signal processing component asdescribed with reference to FIGS. 8 through 10.

FIG. 17 shows a flowchart illustrating a method 1700 for signalscrambling sequence techniques for wireless communications in accordancewith various aspects of the present disclosure. The operations of method1700 may be implemented by a UE 115 or base station 105 or itscomponents as described herein. For example, the operations of method1700 may be performed by a scrambling sequence manager as described withreference to FIGS. 8 through 10. In some examples, a UE 115 or basestation 105 may execute a set of codes to control the functionalelements of the device to perform the functions described below.Additionally or alternatively, the UE 115 or base station 105 mayperform aspects of the functions described below using special-purposehardware.

At block 1705 the UE 115 or base station 105 may identify asynchronization channel containing location information for a commoncontrol resource set within a system bandwidth. The operations of block1705 may be performed according to the methods described with referenceto FIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1705 may be performed by a synchronization channel component asdescribed with reference to FIGS. 8 through 10.

At block 1710 the UE 115 or base station 105 may determine a location ofthe common control resource set within the system bandwidth based atleast in part on the location information. The operations of block 1710may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1710 may be performed by a common control resource component asdescribed with reference to FIGS. 8 through 10.

At block 1715 the UE 115 or base station 105 may identify a cell ID anda slot or subframe index for the common control resource set. Theoperations of block 1715 may be performed according to the methodsdescribed with reference to FIGS. 1 through 7. In certain examples,aspects of the operations of block 1715 may be performed by aslot/subframe index component as described with reference to FIGS. 8through 10.

At block 1720 the UE 115 or base station 105 may identify a reference RElocation within the system bandwidth. The operations of block 1720 maybe performed according to the methods described with reference to FIGS.1 through 7. In certain examples, aspects of the operations of block1720 may be performed by a scrambling sequence identification componentas described with reference to FIGS. 8 through 10.

At block 1725 the UE 115 or base station 105 may generate a scramblingsequence based at least in part on the cell ID, the slot or subframeindex, and the reference RE location. The operations of block 1725 maybe performed according to the methods described with reference to FIGS.1 through 7. In certain examples, aspects of the operations of block1725 may be performed by a scrambling sequence identification componentas described with reference to FIGS. 8 through 10. In some examples,identifying the reference RE location may comprise identifying aconstant fixed offset based at least in part on at least one of a PBCHor RMSI.

At block 1730 the UE 115 or base station 105 may apply the scramblingsequence to a reference signal REs starting at the reference RE locationbased on the generated scrambling sequence. The operations of block 1730may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1730 may be performed by a signal processing component asdescribed with reference to FIGS. 8 through 10.

At block 1735 the UE 115 or base station 105 may process one or more ofthe reference signal, the control signal, or the data signal, based atleast in part on the scrambling sequence. The operations of block 1735may be performed according to the methods described with reference toFIGS. 1 through 7. In certain examples, aspects of the operations ofblock 1735 may be performed by a signal processing component asdescribed with reference to FIGS. 8 through 10.

It should be noted that the methods described above describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Furthermore, aspects from two or more of the methods may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and other systems.The terms “system” and “network” are often used interchangeably. A codedivision multiple access (CDMA) system may implement a radio technologysuch as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc.CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releasesmay be commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. Atime division multiple access (TDMA) system may implement a radiotechnology such as Global System for Mobile Communications (GSM).

An orthogonal frequency division multiple access (OFDMA) system mayimplement a radio technology such as Ultra Mobile Broadband (UMB),Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM,etc. UTRA and E-UTRA are part of Universal Mobile Telecommunicationssystem (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A)are releases of Universal Mobile Telecommunications System (UMTS) thatuse E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, NR, and Global System forMobile communications (GSM) are described in documents from theorganization named “3rd Generation Partnership Project” (3GPP). CDMA2000and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). The techniques describedherein may be used for the systems and radio technologies mentionedabove as well as other systems and radio technologies. While aspects anLTE or an NR system may be described for purposes of example, and LTE orNR terminology may be used in much of the description, the techniquesdescribed herein are applicable beyond LTE or NR applications.

In LTE/LTE-A networks, including such networks described herein, theterm evolved node B (eNB) may be generally used to describe the basestations. The wireless communications system or systems described hereinmay include a heterogeneous LTE/LTE-A or NR network in which differenttypes of evolved node B (eNBs) provide coverage for various geographicalregions. For example, each eNB, gNB or base station may providecommunication coverage for a macro cell, a small cell, or other types ofcell. The term “cell” may be used to describe a base station, a carrieror component carrier associated with a base station, or a coverage area(e.g., sector, etc.) of a carrier or base station, depending on context.

Base stations may include or may be referred to by those skilled in theart as a base transceiver station, a radio base station, an accesspoint, a radio transceiver, a NodeB, eNodeB (eNB), next generation NodeB(gNB), Home NodeB, a Home eNodeB, or some other suitable terminology.The geographic coverage area for a base station may be divided intosectors making up only a portion of the coverage area. The wirelesscommunications system or systems described herein may include basestations of different types (e.g., macro or small cell base stations).The UEs described herein may be able to communicate with various typesof base stations and network equipment including macro eNBs, small celleNBs, gNBs, relay base stations, and the like. There may be overlappinggeographic coverage areas for different technologies.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEswith service subscriptions with the network provider. A small cell is alower-powered base station, as compared with a macro cell, that mayoperate in the same or different (e.g., licensed, unlicensed, etc.)frequency bands as macro cells. Small cells may include pico cells,femto cells, and micro cells according to various examples. A pico cell,for example, may cover a small geographic area and may allowunrestricted access by UEs with service subscriptions with the networkprovider. A femto cell may also cover a small geographic area (e.g., ahome) and may provide restricted access by UEs having an associationwith the femto cell (e.g., UEs in a closed subscriber group (CSG), UEsfor users in the home, and the like). An eNB for a macro cell may bereferred to as a macro eNB. An eNB for a small cell may be referred toas a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB maysupport one or multiple (e.g., two, three, four, and the like) cells(e.g., component carriers).

The wireless communications system or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations may have similar frame timing, andtransmissions from different base stations may be approximately alignedin time. For asynchronous operation, the base stations may havedifferent frame timing, and transmissions from different base stationsmay not be aligned in time. The techniques described herein may be usedfor either synchronous or asynchronous operations.

The downlink transmissions described herein may also be called forwardlink transmissions while the uplink transmissions may also be calledreverse link transmissions. Each communication link describedherein—including, for example, wireless communications system 100 and200 of FIGS. 1 and 2—may include one or more carriers, where eachcarrier may be a signal made up of multiple sub-carriers (e.g., waveformsignals of different frequencies).

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Also, as used herein, including in the claims, “or” as usedin a list of items (for example, a list of items prefaced by a phrasesuch as “at least one of” or “one or more of”) indicates an inclusivelist such that, for example, a list of at least one of A, B, or C meansA or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, asused herein, the phrase “based on” shall not be construed as a referenceto a closed set of conditions. For example, an exemplary step that isdescribed as “based on condition A” may be based on both a condition Aand a condition B without departing from the scope of the presentdisclosure. In other words, as used herein, the phrase “based on” shallbe construed in the same manner as the phrase “based at least in parton.”

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media maycomprise RAM, ROM, electrically erasable programmable read only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave are included in the definition of medium. Disk and disc,as used herein, include CD, laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication, comprising:identifying a synchronization channel containing location informationfor a common control resource set within a system bandwidth; determininga location of the common control resource set within the systembandwidth based at least in part on the location information and areference numerology; identifying a center frequency of a wirelesschannel; determining, based at least in part on the identified centerfrequency, a scrambling sequence for one or more of a reference signal,a control signal, or a data signal, for use in demodulating the commoncontrol resource set; and processing one or more of the referencesignal, the control signal, or the data signal, based at least in parton the scrambling sequence.
 2. The method of claim 1, wherein thewireless channel comprises the synchronization channel, and wherein: thecenter frequency of the wireless channel is different than a centerfrequency of the system bandwidth.
 3. The method of claim 1, wherein thewireless channel comprises the synchronization channel, and wherein: thecenter frequency of the wireless channel is the same as a centerfrequency of the system bandwidth.
 4. The method of claim 1, furthercomprising: identifying a raster of synchronization channel centerfrequencies within the system bandwidth; and identifying the centerfrequency of the wireless channel as one of the synchronization channelcenter frequencies on the raster of the synchronization channel centerfrequencies, wherein the wireless channel comprises the synchronizationchannel.
 5. The method of claim 1, wherein the wireless channelcomprises the synchronization channel, further comprising: identifying acell ID, a slot index, or a subframe index associated with the commoncontrol resource set; generating the scrambling sequence based at leastin part on the cell ID, the slot index, or the subframe index, and thecenter frequency of the wireless channel, wherein determining thescrambling sequence is based at least in part on the generating; andapplying the scrambling sequence to a signal pattern of one or more ofthe reference signal, the control signal, or the data signal, whereinprocessing the one or more of the reference signal, the control signal,or the data signal, is based at least in part on applying the scramblingsequence to the signal pattern.
 6. The method of claim 1, wherein theprocessing one or more of the reference signal, the control signal, orthe data signal, further comprises: identifying a reference resourceelement (RE) associated with a received signal; and filling thescrambling sequence for REs of one or more of the reference signal, thecontrol signal, or the data signal, starting at the reference RE basedon the scrambling sequence.
 7. The method of claim 6, furthercomprising: receiving, in a physical broadcast channel (PBCH), orremaining minimum system information (RMSI), or a combination thereof,an indication of a constant fixed offset from the synchronizationchannel, wherein identifying the reference RE is based at least in parton the constant fixed offset.
 8. The method of claim 1, furthercomprising: identifying that the common control resource set istransmitted on a second carrier that is different than a first carrierused to transmit the synchronization channel, wherein the wirelesschannel comprises a second synchronization channel, wherein determiningthe scrambling sequence for one or more of the reference signal, thecontrol signal, or the data signal, for use in demodulating the commoncontrol resource set is based at least in part on the center frequencyof the second synchronization channel.
 9. The method of claim 8, furthercomprising: receiving, from a base station, an indication of the secondsynchronization channel, wherein identifying the center frequency of thesecond synchronization channel is based at least in part on theindication.
 10. An apparatus for wireless communication, in a systemcomprising: a processor; memory in electronic communication with theprocessor; and instructions stored in the memory and operable, whenexecuted by the processor, to cause the apparatus to: identify asynchronization channel containing location information for a commoncontrol resource set within a system bandwidth; determine a location ofthe common control resource set within the system bandwidth based atleast in part on the location information and a reference numerology;identify a center frequency of a wireless channel; determine, based atleast in part on the identified center frequency, a scrambling sequencefor one or more of a reference signal, a control signal, or a datasignal, for use in demodulating the common control resource set; andprocessing one or more of the reference signal, the control signal, orthe data signal, based at least in part on the scrambling sequence. 11.The apparatus of claim 10, wherein the wireless channel comprises thesynchronization channel, and wherein: the center frequency of thewireless channel is different than a center frequency of the systembandwidth.
 12. The apparatus of claim 10, wherein the wireless channelcomprises the synchronization channel, and wherein: the center frequencyof the wireless channel is the same as a center frequency of the systembandwidth.
 13. The apparatus of claim 10, wherein the instructions arefurther executable by the processor to cause the apparatus to: identifya raster of synchronization channel center frequencies within the systembandwidth; and identify the center frequency of the wireless channel asone of the synchronization channel center frequencies on the raster ofsynchronization channel center frequencies, wherein the wireless channelcomprises the synchronization channel.
 14. The apparatus of claim 10,wherein the instructions are further executable by the processor tocause the apparatus to: identify a cell ID, a slot index, or a subframeindex associated with the common control resource set; generate thescrambling sequence based at least in part on the cell ID, the slotindex, or the subframe index, and the center frequency of the wirelesschannel, wherein determining the scrambling sequence is based at leastin part on the generating; and apply the scrambling sequence to a signalpattern of one or more of the reference signal, the control signal, orthe data signal, wherein processing the one or more of the referencesignal, the control signal, or the data signal, is based at least inpart on applying the scrambling sequence to the signal pattern.
 15. Theapparatus of claim 10, wherein the instructions to process one or moreof the reference signal, the control signal, or the data signal, arefurther executable by the processor to cause the apparatus to: identifya reference resource element (RE) associated with a received signal; andfill the scrambling sequence for REs of one or more of the referencesignal, the control signal, or the data signal, starting at thereference RE based on the scrambling sequence.
 16. The apparatus ofclaim 15, wherein the instructions are further executable by theprocessor to cause the apparatus to: receive, in a physical broadcastchannel (PBCH), or remaining minimum system information (RMSI), or acombination thereof, an indication of a constant fixed offset from thesynchronization channel, wherein identifying the reference RE is basedat least in part on the constant fixed offset.
 17. The apparatus ofclaim 10, wherein the instructions are further executable by theprocessor to cause the apparatus to: identify that the common controlresource set is transmitted on a second carrier that is different than afirst carrier used to transmit the synchronization channel, wherein thewireless channel comprises a second synchronization channel, whereindetermining the scrambling sequence for one or more of the referencesignal, the control signal, or the data signal, for use in demodulatingthe common control resource set is based at least in part on the centerfrequency of the second synchronization channel.
 18. The apparatus ofclaim 17, wherein the instructions are further executable by theprocessor to cause the apparatus to: receive, from a base station, anindication of the second synchronization channel, wherein identifyingthe center frequency of the second synchronization channel is based atleast in part on the indication.
 19. An apparatus for wirelesscommunication, comprising: means for identifying a synchronizationchannel containing location information for a common control resourceset within a system bandwidth; means for determining a location of thecommon control resource set within the system bandwidth based at leastin part on the location information and a reference numerology; meansfor identifying a center frequency of a wireless channel; means fordetermining, based at least in part on the identified center frequency,a scrambling sequence for one or more of a reference signal, a controlsignal, or a data signal, for use in demodulating the common controlresource set; and means for processing one or more of the referencesignal, the control signal, or the data signal, based at least in parton the scrambling sequence.
 20. The apparatus of claim 19, wherein thewireless channel comprises the synchronization channel, and wherein: thecenter frequency of the wireless channel is different than a centerfrequency of the system bandwidth.
 21. The apparatus of claim 19,wherein the wireless channel comprises the synchronization channel, andwherein: the center frequency of the wireless channel is the same as acenter frequency of the system bandwidth.
 22. The apparatus of claim 19,further comprising: means for identifying a raster of synchronizationchannel center frequencies within the system bandwidth; and means foridentifying the center frequency of the wireless channel as one of thesynchronization channel center frequencies on the raster ofsynchronization channel center frequencies, wherein the wireless channelcomprises the synchronization channel.
 23. The apparatus of claim 20,wherein the means for processing one or more of the reference signal,the control signal, or the data signal, further comprise: means foridentifying a reference resource element (RE) associated with a receivedsignal; and means for filling the scrambling sequence for REs of one ormore of the reference signal, the control signal, or the data signal,starting at the reference RE based on the scrambling sequence.
 24. Theapparatus of claim 23, further comprising: means for receiving, in aphysical broadcast channel (PBCH), or remaining minimum systeminformation (RMSI), or a combination thereof, an indication of aconstant fixed offset from the synchronization channel, whereinidentifying the reference RE is based at least in part on the constantfixed offset.
 25. The apparatus of claim 20, further comprising: meansfor identifying that the common control resource set is transmitted on asecond carrier that is different than a first carrier used to transmitthe synchronization channel, wherein the wireless channel comprises asecond synchronization channel, wherein determining the scramblingsequence for one or more of the reference signal, the control signal, orthe data signal, for use in demodulating the common control resource setis based at least in part on the center frequency of the secondsynchronization channel.
 26. The apparatus of claim 25, furthercomprising: means for receiving, from a base station, an indication ofthe second synchronization channel, wherein identifying the centerfrequency of the second synchronization channel is based at least inpart on the indication.
 27. A non-transitory computer readable mediumstoring code for wireless communication, the code comprisinginstructions executable by a processor to: identify a synchronizationchannel containing location information for a common control resourceset within a system bandwidth; determine a location of the commoncontrol resource set within the system bandwidth based at least in parton the location information and a reference numerology; identify acenter frequency of a wireless channel; determine, based at least inpart on the identified center frequency, a scrambling sequence for oneor more of a reference signal, a control signal, or a data signal, foruse in demodulating the common control resource set; and process one ormore of the reference signal, the control signal, or the data signal,based at least in part on the scrambling sequence.
 28. Thenon-transitory computer readable medium of claim 27, wherein theinstructions are further executable by the processor to: identify araster of synchronization channel center frequencies within the systembandwidth; and identify the center frequency of the wireless channel asone of the synchronization channel center frequencies on the raster ofsynchronization channel center frequencies, wherein the wireless channelcomprises the synchronization channel.
 29. The non-transitory computerreadable medium of claim 27, wherein the instructions to process one ormore of the reference signal, the control signal, or the data signal,are further executable by the processor to: identify a referenceresource element (RE) associated with a received signal; and fill thescrambling sequence for REs of one or more of the reference signal, thecontrol signal, or the data signal, starting at the reference RE basedon the scrambling sequence.